Distance-measuring instrument.



J. HUMBRBCHT. DISTANCE MBASURING INSTRUMENT. APPLICATION FILED SEPT. o, 1912.

'1,088,7o1- Patented Mar. 3, 1914.

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l of the rays coming -UNTTED sTATns PATENT OFFICE.

JULES HUMBRECHT, 0F GROSS--LICHTERFEL'DE NEAR OFOPTISCHE ANSTALT C. I. GOERZ AKTIENGESELLSCHAFT, 0F

TO THE `FIRM BERLIN, GERMANY.

BERLIN, GERMANY, ASSIGNOR DISTANCE-MEASRING INSTRUMENT.

Application filed September To H l1/omit muy concern lic it known that I, .litmus Huiiniucirr, a citizen of the German Empire, and resident of Gross-Lichterfelde, near Berlin, (iermany, have. invented vcertain new and useful ln'iprovcments in and Relating to Disltance-lVTeasuring Instruments, of which the following is a specification.

This invention relates to a distance measuring device provided with two rotatable wedge-shaped transparent plates adapted to produce lateral displacement ot the rays of light coming from' the object the distance of which is to be measured on passing through said wedgesshaped plates.

The new device is illustrated iu the accompanying drawing wherein# Figure 1 shows a middle cross-section through the instrument inserted between a lens andthe ocular of an observer. Figs. 2 and 3 show elevations of the instrument with different positions of images in the field of view. Fig-4 is a section' on the line 4-4 of Fig. 2. Fig. 5 is an elevation ot an embodiment having a modified indicating device.

The two wedge-shaped measuring plates are designated a, b. These plates are formed of a transparent material such as glass and firmly connected with hublil c members of metal each provided with a conical gearing g. Meshing with said coni-- cal gearings g is a pinion g firmly mounted on a shaft j" carrying a knob jt'. Said shaft j is p rovidcd with the further conical gearing I1. meshing with the teeth h of a conical pinion -firlnly connected with a rotatable scale plate i. The scale plate i. is inclosed by an index ring with pointer k. The wedge-shaped plates a, Z) project into a tubular mount c provided with glass plates d', c one on each side of the wedge plates u.. b so that said wedge plates are protected by plates (l, e against injury. On rotating the knob f the wedges a, are rotated .in oppo site directions so that the deviation of rays of light passing through said plates is changed depending on the wedge shape of the plates a, b. The outer edges ot the plates o, b are of circular Jform and arranged in line with each other.

It the instrument is inserted in the path from a distant object the that part of the instrurays pass through b without ment outside the wedge plates a,

.opposite the pointer lc indicates deviation whereas deviation takes place for that part of the rays passingr through the wedge plates u, 7),. the amount ot' tliis deviation depending on the adjustment of plates a, b. It now an object 'of known size is observed and if the plates a, b are so adjusted that the parts of the image of said object separated by the circular edge of plates a, b are displaced with relation to each other to an amount equal to the size of the observed object as illustrated in Fig ot the drawing then the adjustment of plates a., b is characteristic for the distance of said object.. If for instance, the instrument is used Jfor measuring the distance ot men-ofwarv and if it is known that the distance of the top edge of the chimney is 25 meters over the level of the water and if the graduation on the scale plate i is made for objects of this size then the po-int of the graduation the dis tance of said objects. In the case of Figs. 2 and 3 of the drawing it is assumed that the unit of the graduation is-equal to 100 meters so that the distance of the ship visible in thc ticld of view of Fig. 3 would be equal to 2500 meters.

The graduation shown in Figs. Q and 3 is a daptcd to the observation of objects of definite known size, for instance 25 meters as in the above example. If the objects of observation are of different size then the distance cannot be directly read on the scale plate but must he found by calculation. For instance if an object of 2.5 meters in si/.e is observed and the pointer 7c is again opposite the point of the scale with the denomination 25 then the distance of such object would be 250 mcters. In order to avoid such 'calculation the graduation of the scale device may he made as illustrated in Fig'. 5 of the drawing where m is a lixed distance scale engraved in a fixed transparent plate covering scale plate i', such fixed distance scale lcorresponding to the pointer r in Figs. 2 and 3 whereas the grad uation ot' the scale plate i consists in a set ot curved lines. The fixed transparent plate carrying the distance scale m may be mounted in any suitable way (not shown on the drawing) on the casing of the instrument. "he adjustinent of the instrument is the same as above described, that is to say on observation of an object of known size plates a and b are so adjusted by rotating knob f that the parts'of the image appearing one at Patented M ar. 3, 1914.

9,1912. serifunoalazes.

,the side of the other are displaced with relation to each other for a distance equal t0 the size of the image of the object as appears from Fig. 5 oi' the drawing. The distance of the object is indicated by that curved line on scale plate z' which crosses that point oit' thev fixed distance scale which indicates the size of the observed object. If for instance in the case of Fig. 5Y of the drawing the distance ot' the observed ship from the level of the water to the top edge of the chimney isv again 25 meters then the distance or" said ship indicated by the instrw ment would be 1000 meters because the vcurved line corresponding to a distance of 1000 meters crosses the point 25 of the distance scale.

The measuring device with the rotatable Wedge-shaped'disks a, Z) forms a unit for 1t self and could be used for distance measur- Aing purposes without further appliances.

However it would practically hardly be possible ltosee the distant objects sufficiently sharp in order .to vallow exact adjustment of the wedges'a, Therefore, the instrument is practically used as a supplement of a telescope and in this case is placed before the ocular. Such arrangement is shown in Fig. l of the drawing where the ocular is desigf nated n. In view of the fac-t that the eye Z of the observer must be positioned behind the measuring device it is necessary to use for the purpose in question telescopes having their eXit-pupil at a comparatively large distance from the ocular as is the case with the device shown in'Fig. l of the drawing. ln this case the two parts of the image are not clearly separated from each other by the edges of the wedge-shaped plates, because the edges are not positioned in an image plane of the telescope. The parts of .the image will overlap-as however not shown on the drawing-this being of special advantage in the observation of moving objects as seen from ship board;

What I claim is l. In a distance measuring instrument two pivotally mounted members having wedge shaped transparent plates, a casing having a with each other, an actuating device for plate coupled with said actuating device for the lwedge-shaped plates.

In a distance measuringinstrument two wedge-shaped transparent plates each firmly connected ywith a metal hub piece, a casing having atubular part', said Wedge-shaped transparent plates projecting into said tubular part oi: the casing from one side and being provided with circular edges in line with each other, the metal hubs of said wedge-shaped plates pivotally mounted so as to be rotatable about the axis of lthe circular edgesof the transparent plates and each provided with a toothed edge, an actuating shaft, a-pinion thereon meshing with the toothed edges of the wedgeshaped plates, a rotatably mounted scale disk mounted substantially parallel to said actuating shaft, a gear connection between said scale disk and said shaftv adapted to rotate the scale disk. with higher speed than the wedge-shaped plates.

3. In adistance measuring instrument tWo pivotally mounted members having wedgeshaped transparent plates, a casing having a tubular plates projecting into said tubular 'casing from one side, the projecting edges of said plates having a circular form and being in line with each other', two circular transparent plates mounted within said tubular casing one on each'side of th pair of lwedgeshaped plates so as to form a protecting receptacle for same.

In testimony 'whereof I have signed this specification in the presence of two subscribing witnesses.

JULES HUMBRECHT.

Witnesses;

WOLDEMAR Hiv rr, HENRY Hnsrniz.

part the transparent wedge-shaped 

